1. Field of the Invention
The present invention relates generally to the art of soldering or brazing and, more specifically, to a held-held device to dispense lengths of solder wire for use in soldering plumbing joints and like applications.
2. Description of Related Art
A successful device for dispensing solder wire or similar materials should be easily operated with one hand so that the operator's other hand can be used to hold a torch or other heat source. Furthermore, the device should be adaptable so that different diameters of solder wire can be easily used. A logical shape for a one-hand-operated dispenser is a gun-like shape that can be operated by pulling a "trigger." Such a shape allows the unit to be easily grasped with one hand and operated by using one's fingers to grasp and squeeze a trigger-like dispensing lever. Preferably, a single pull of the "trigger" should dispense a length of wire sufficient for any soldering job because it is virtually impossible to provide an even-soldered joint if the trigger must be operated repeatedly during the soldering operation.
Although the prior art contains a number of devices that combine a solder dispenser and a soldering iron, no devices have been directed towards dispensing greater lengths of larger-diameter solder for use in soldering plumbing and the like. Several prior art devices have adopted a "gun-like" shape, but they all suffer from a lack of adaptability to different diameter solder wires and/or an inability to dispense sufficient solder in a single operation. For example, U.S. Pat. No. 2,432,428 to Lang shows a combination solder dispenser and soldering iron. The unit has a gun-shaped housing and operates by a pawl-bearing trigger member which engages gear teeth on the edge of a grooved roller. When the roller is rotated by the pawl, the solder wire, which is held in the grooved roller by a companion roller, is advanced. However, the unit is limited to solder wire with a diameter small enough to fit into the grooved roller.
The pawl/gear tooth interaction forms a ratchet so that the solder moves in one direction only. One can readily appreciate that the maximum length of solder wire that can be dispensed in one movement is equal to a circumference of the grooved roller. In actual practice, the mechanism is constructed so that only about a length of solder equal to one-quarter of the circumference of the roller can be dispensed because a single pull of the trigger turns the roller only about one-quarter revolution. One practical way to increase the length of solder dispensed is to increase the size of the grooved roller. However, the roller size is limited by a desire to provide a compact unit.
Another combination soldering iron/solder dispenser is shown in U.S. Pat. No. 2,952,763 to Gustafsson. In this device, the solder wire runs between a detente-bearing cog wheel and a roller. A trigger member engages the cog wheel so that pulling the trigger member will rotate the cog wheel and advance the solder. A wire spring acts as a pawl, preventing backwards rotation of the cog wheel when the trigger member returns to an initial position. This device, like the first-described unit, is not readily adaptable to various diameters of larger solder wire. Furthermore, the length of solder dispensed per pull of the trigger member is limited by the cog wheel's diameter.
U.S. Pat. No. 3,852,565 to Kager shows another solder dispenser. Again, a toothed wheel is used to dispense the solder wire. The toothed wheel, driven by a trigger lever, presses the solder wire against a pressure spring. This arrangement allows the device to accommodate solder wire of varying diameters. However, the maximum length of dispensed solder is limited by a diameter of the toothed wheel.
U.S. Pat. No. 4,521,673 to Oury also uses a toothed drive wheel which presses the solder wire against a spring-loaded roller. This arrangement allows for some variation in the diameter of the dispensed solder, but the dispensed length is again limited by a diameter of the toothed wheel. Another variation on the toothed drive wheel is shown in U.S. Pat. No. 2,751,485 to Sauer. Again, the dispenser is gun-shaped with the dispensing action effected by pulling a trigger lever. Here a toothed wheel rotates through the action of a pawl attached to the trigger lever. Changes in solder diameter are accommodated by having the drive wheel axle mounted in slots so that the drive wheel slides into contact with the solder wire regardless of the diameter of the wire. However, a diameter of the feed wheel still controls the maximum length of the dispensed solder.